With the popularity and industrialization of technology of Internet of things, the application amount of sensors increases greatly. Generally, analog signal of the sensor may be further processed only after being matched and transmitted by a transmitter, thus, the quantity demand and functional requirement for transmitters also increase.
FIG. 1 is a schematic diagram illustrating a typical topology of sensors and transmitters in the prior art, and connection relationships among respective components contained in the topology are shown in FIG. 1. As shown in FIG. 1, for different kinds of sensors S1, S2, . . . and Sn, transmitters T1, T2, . . . and Tn in the prior art represented by dashed boxes need to perform signal amplification by different amplifiers A1, A2, . . . and An which are provided respectively and are not versatile, perform analog/digital conversion by independent analog/digital (A/D) converters C1, C2, . . . and Cn respectively, and perform digital signal processing by separate digital interface circuits I1, I2, . . . and In. If it is intended to use a single line for transferring output signals, it is further required to perform multiplexing by an n-to-1 channel interface circuit M, such as a programmable logic controller (PLC).
In the prior art, since there are various kinds of sensors, indexes of the sensors are divergent, and generally one sensor can only use a particular transmitter, that is, one sensor matches with one transmitter, the transmitters can not be shared and can not be used versatilely, which may result in the following problems:
1. The cost for constructing a monitoring system is high. In a monitoring system, the cost of transmitters usually far exceeds the cost of sensors. Thereby, with the increase in the number of the sensors, the cost grows exponentially.
2. The production cost of the transmitter is high. The transmitters for sensors of different signals, even for a single kind of sensors of the same kind of signal must be used dedicatedly. Thus, not only the user cost increases, but also the producer cost increases. Since the types of the transmitters to be produced are too many, the quantity of each kind of sensors would not be large. Thus, in order to apportion the cost, the price of a single transmitter would be hard to be reduced, and mass production would be hard to be conducted.
3. Electricity waste exists and the life of the system is short. The number of channels processed by the transmitters is low, the transmitters can not be multiplexed, and even if no data is required, each transmitter must still be in a working condition, which not only causes a waste of electricity, but also leads to a short life of the system. In general, one monitoring system is equipped with a plurality of sensors in different kinds, thus, in conditions of slowly data collecting, such as in normal systems where collection intervals are more than ten minute, or even one or two hours or one day, the phenomena of electricity waste and short system life is especially serious.